Plaster composition.



UNITED STATES PATENT OFFICE.

JAMES EDWIN FAIRFAX, OF AIKEN, SOUTH CAROLINA, ASSIGNOR OF TWO-THIRDS T0JOHN M. RICHARDSON, 0F AIKEN, SOUTH CAROLINA.

ILASTER COMPOSITION.

No Drawing.

To all whom it may concern:

Be it known that I, JAMES E. FAIRFAX, a citizen of the United States,and a resident of Aiken, in the county of Aiken and State of SouthCarolina, have invented a new and Improved Plaster Composition, of whichthe following is a full, clear, and exact deseription.

My invention relates to plaster compositions, and has reference moreparticularly to a composition comprising substances that will make thecomposition work more evenly, moisture proof, hard, and hold the set.

The object of the invention is to provide an inexpensive waterproofplaster composition which can be used on wood as well as metal laths,which can be worked in any desired Way, and which does not crack norchip off.

The ingredients I use for forming this plaster composition are asfollows: plaster of Paris, slaked lime, kaolin, sand, fibered hay, andRochelle salt.

The slaked lime I use is prepared as follows: The lime in bulk is throwninto a receptacle, which may be any suitable building of any suitablematerial. While the lime is being thrown or shoveled into the receptacleit is sprayed with water, care being taken not to slaken the lime atonce but to produce a slow slakening of the lime. The lime so sprayed isleft in the receptacle for twenty-four hours; then it is ground. I havefound by. experience that lime slaked in this way is stronger than theordinary and so-called air slaked lime. The sand I use is first driedand then screened; and it must be sharp and clean. The kaolin I use isin a dry and powdered form. The hay is fibered by running it through acotton gin, but it can be fibered in any other suitable Way. The decayof the fibered hay is prevented by the lime. The Rochelle salt used isfinely powdered before mixing with the other ingredients.

The proportion of the ingredients stated that I prefer to use is asfollows: To every one ton of my composition I use five hun-Specification of Letters Patent.

Application filed July 9, 1913.

Patented June 9, 1914.

Serial No. 778,063.

dred pounds of plaster of Paris, five hundred pounds of slaked lime, onehundred pounds of kaolin, eight hundred and ninetythree pounds of sand,six pounds of fibered hay and one pound of Rochelle salt. In per cent.it will be as follows: 25% of plaster of Paris, 25% of slaked lime, 5%of kaolin, 44.65% of sand, 3% of fibered hay, and 05% of Rochelle salt.

The plaster of Paris and the slaked lime help to make the compositionhard. The kaolin makes the same to work more evenly and makes itmoisture proof. The fibered hay is the binding element in thecomposition. The Rochelle salt holds the set of the composition andincreases the hardness of the same.

The composition made as above described can be used on brick, stone,wood and metal laths. It has no injurious e'llect on metal of any kind;it spreads easily; and it can be water floated. It works well under therod, darby and float. It does not crack or chip off. It is very firmwithout a superficial coat, but leaving out the sand and hay of thecomposition it can be used as an extra coat, forming a beautiful, hard,white finish. The extra or second coat should be put on the same day asthe first coat.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

1. A plaster composition comprising ingredients substantially inproportion as fol lows: plaster of Paris, 25%; slaked lime, 25% kaolin,5%; sand, 44 .65%; fibered hay,

3%; Rochelle salt, 05%.

2. A plaster composition comprising plaster of Paris and slaked lime inequal proportions mixed with kaolin, fiber, Rochelle salt and sand.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES EDWIN FAIRFAX. lVitnesses J. B. SALLEY, Gno. 'W. CROFT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

